1. Field of the Invention
This invention relates to a debris intercepting screen, positioned in the opening of curb inlets, for reducing water pollution in natural lakes, rivers, streams, and oceans.
2. Description of the Prior Art
The presence of debris in our waterways and along our shorelines continues to pose serious health, economic, and environmental consequences. The sight of waste materials such as aluminum cans, glass bottles, plastic containers, shoes, and the like, floating on streams and waterways is a visible reminder to the public of contamination and pollution of the water supply.
Much of the debris littering our watersupply areas and beaches does not wash ashore from the ocean, but originates on land, usually as a result of inadequate waste management practices and undiscriminating roadway liter from traveling motorists.
The effect of debris moving from inland areas through judiciously placed curb inlets to convey storm water run-off from paved roads, streets, and highways to discharge locations, such as drainage ponds, natural rivers, lakes, and streams, is evident in the waterways of many urban communities.
Presently, there is no attempt to prevent non-perishable and slow decomposing debris from entering curb inlets which serves which are connected to the storm sewer drainage systems. Conventional curb inlets simply provide an unobstructed opening in the curb construction. The usual opening dimensions of a curb inlet without an extension is 5 feet (length).times.6" (height), 10 feet (length).times.6" (height) for curb inlets with one extension, and 15 feet (length).times.6" (height) for curb inlets with two extensions.
Too often curb inlets are used as inconspicuous garbage receptacles. Some debris remain inside storm sewers, eventually accumulates and clogs the drainage pipe until they decompose (which may take years depending on the material) or until heavy rains push them through the drainage system.
An analysis of underwater debris collected revealed that 62.4% were composed of materials such as plastic bottles, cups, glass pieces and metal cans. Furthermore, the decomposition time for plastic materials is approximately 164 years. It is evident that public awareness campaigns, to promote citizen responsibility and environmental stewardship regarding urban inland waste and its impact on aquatic environments, are positive steps but more is needed-water is a valuable natural resource. As the worldwide population increases, if nothing is done to intercept trash before entering the storm sewer drainage systems, it is inevitable there will be an enormous amount of debris deposited in our "fishable and swimmable" lakes, rivers, and streams.
Furthermore, the construction of streets, highways, office buildings, shopping centers, restaurants, apartment houses, sports complexes and the like, produces more trash which is persuaded by rain and winds or traveling motorists, into curb inlets. It is unacceptable to allow this continued and subtle method of polluting the natural watersupply areas.
Prior art contains disclosures of sewage systems in which filters are placed within the throat of curb inlets to prevent sediment and solid foreign objects from entering drainage pipes and some of these include a removable basket in which the filtered-out solid material is retained to facilitate cleaning and replacement. However, in the prior art, the filters, when fUll of sediment, can obstruct flow of water, are usually made of metals (which are sometimes the source of theft), are expensive to manufacture, are extremely heavy, and require various machines or a number of workers to install .
U.S. Pat. No. 658,639 (Guion) discloses a receiving basin for a sewer system which is divided by a vertical screen into compartments. A removable metal basket is normally housed in the compartments which contain filtration material.
U.S. Pat. No.809,201 Lutz) discloses a receiving basin for sewage system that receives surface water from streets. The receiving basin is intended to catch sediment in the water and prevent it fro m being carried into the sewer. The basin houses a removable basket into wh ich in coming surfac e water is directed. T he basket has a main, screened opening through which surface water passes from the basket through the basin, and subsidiary outlets. Subsidiary outlet allows water to escape around the basket if the basket is full of sediment. U.S. Pat. No. 1,746,121 (Levy) discloses a catch basin for a sewer in which the basin is provided between its inlet and the sewer, with a removable basket into which incoming water is directed and which re tains solid materials.
U.S. Patent No. 2,102,31 (gan) discloses a removable rece ptacle for inse rtion within a receiv ing basin of a sewer. The receptacle has a spiral arrangement of discharge ports through which incoming water ca n flow to the sewer.
U.S. Pat. No. 2,615,526 (Lane) discloses a catch basin for a sewer which is provided with a removal filter basket formed of a screen, angle irons and sheets.
U.S. Pat. No. 4,382,713 (Kawahara) discloses an apparatus for reducing wastage for water draining from pavements by letting storm runoff move into a container filled with pebbles or foam concrete so that the water can be disbursed into the underlying ground.
U.S. Pat. No. 4,419,232 (Arntyr) discloses a filter for outdoor drains in roadways, etc., comprising a grating, below which is mounted a course filtering wire basket and below that, a fine filtering bag of flexible water-permeable cloth fabric.
U.S. Pat. No. 4,594,157 (McGowan) discloses an expensive metal inlet clamp for affixing to a cover over a storm sewer inlet to mount a screen to protect the curb entrance to the sewer, comprising a generally F-shaped bracket. However, the device utilizes steel or cast iron clamps and can only be used with curb inlets having a cast iron or steel cover. Most industry standard curb inlets manufactured presently, are fabricated out of concrete or are pre-cast concrete units. Thus, this device cannot be used with industry standard pre-cast or cast in place concrete curb inlets. The device also uses thumb bolts, nuts, washers, and the entire assembly is heavy--increasing the compressive stress load on the structure. Installation of the device is extremely labor intensive.
U.S. Pat. No. 5,133,619 (Murfae), discloses a removable metal filter basket housed in a basin disposed in an alternative runoff path upstream from the stormwater receiving basin. The basket contains a dischargeable filtration media and lifting channels which enable the basket to be removed from the basin by the tines of conventional waste disposal vehicles.
U.S. Pat. No. 5,232,587 (Hegemier) discloses a curb inlet filter that is placed into the throat of an inlet and composed of a perforated aluminum section riveted to a tubular steel frame. A grate type rack is constructed across hydraulic openings. The metal filter has at least one welded handle and the entire filter rests on angle supports that are retrofitted to the interior walls of the inlet made of welded aluminum and tubular steel frames placed on retrofitted angle iron supports, mounted on the walls of the storm sewer basin, to convey stormwater flows. In order to install the device, holes would have to be drilled into the walls of the inlet for the angle iron supports. Drilling the holes into the inlet walls combined with the heavy weight of the device when installed effects the overall load capacity and structural integrity of the inlet. The heavy weight of these products also increase transportation costs. There is an enormous amount of time to install this device and it requires skilled workers to manufacture and perhaps several individuals to install the device. At least one lane of traffic would have to be closed during the installation process.
U.S. Pat. No. 5,403,474 (Emery), discloses a portable curb inlet sediment filter which has a box filter frame, to be filled with particulate filter medium, such as gravel, for sediment removal, and an overflow chamber. The overflow chamber has at least one baffle panel in order to provide a hydraulic opening and a peripheral end cap chamber. The end cap chamber is gravel filled in order to clarify water escaping around the front of the frame and into the hydraulic opening through the side panel. The filter frame and baffle panels are a mesh construction having apertures smaller in size than the particles of gravel to be contained. This device is bulky and is placed in front of curb inlets thus protruding into the street which could be traffic hazard to passing motorist, especially during night-time driving. Also, if damaged or struck by a vehicle, the gravel and other filtration material from the device can damage the vehicle or litter the pavement or surrounding area. The device was designed only to be used as a temporary sediment control measure and can not be manufactured with various spaced hydraulic openings. The device can also impede snow plows and street maintenance equipment by protruding into traffic lanes.
The prior art discloses filters which combine cinder blocks, wire screens, stone riprap, fabric fences, straw bales, sand bags, or sack gabions staked tightly around the perimeter of the inlet, to serve as a Storm Water Pollution Prevention Plan (SWPPP) measure. Filters constructed with these materials are hazardous to the traveling public because they are sometimes placed within clearzones of the roadway and may protrude into traffic lanes, necessitate frequent maintenance, are labor intensive, costly, and clog the storm sewer drainage pipes when loosened or disturbed.
The disadvantages of the prior art are overcome by the present invention, hereinafter disclosed which is light-weight, does not require clamps, welds, nuts, bolts, screws, drilling, is reliable due to the simplistic design, is self-relieving, is inexpensively manufactured and maintained compared to the prior art.